I am looking to hook up some blue LED strips into my 2010 mazda 3 sport. possibly under my door or by peoples feet. I would like them to turn on like the dome lights do (everytime i open a door). I cannot find a door sensor and do not want to pull and prode at every wire i see. Can someone tell me instructions on where i may find a wire that leads to the domelights or to the sensor in the door which tells the lights that a door is open?

 

so you just want them to come on when the door is opened then go back off when the door is closed??

 

Try using the wires noted in this install of the JDM footwell lamps on the 1st gen. Assuming that works then your lights will come on: when you unlock the doors via the remote, when you open a door, or when you turn off the ignition. They'll turn off when you: turn the ignition to ACC, lock the doors via the remote, or about 30 seconds after the last time a door was closed and not locked.

Bear in mind that the dome lights are a constant 12v and a switched ground. Just FYI.